Automatic replenishment,calibration and metering system for automatic processors

Abstract: Described herein is a low volume processor for processing photosensitive material which utilizes a narrow horizontal processing channel (25). A replenishment pump calibration system is integrated into the processor so that no manual measurements or special tools are required to set replenishment solution rates.

Description: Field of the Invention The invention relates to automatic processors and is more particularly concerned with an automatic replenishment, calibration and metering system for such processors. Background of the Invention The processing of photosensitive material involves a series of steps such as developing, bleaching, fixing, washing, and drying. These steps lend themselves to mechanization by conveying a continuous web of film or cut sheets of film or photographic paper sequentially through a series of stations or tanks, each one containing a different processing liquid appropriate to the process step at that station. There are various sizes of photographic film processing apparatus, i.e., large photofinishing apparatus and microlabs. A large photofinishing apparatus utilizes tanks which contain approximately 100 liters of each processing solution. A small photofinishing apparatus or microlab utilizes tanks which may contain less than 10 liters of processing solution. The chemicals contained in the processing solution: cost money to purchase; change in activity and are seasoned by the constituents of the photosensitive material which leach out during the photographic process; and after the chemicals are used the chemicals must be disposed of in an environmentally safe manner. Thus, it is important in all sizes of photofinishing apparatus to reduce the volume of processing solution. The prior arts suggest various types of replenishing systems which add or subtract specific chemicals to the processing solution to maintain a consistency of photographic characteristics in the material developed. Photosensitive material processing equipment typically consists of several large volume tanks of processing solution that the exposed photosensitive material is driven or towed through to produce an image, as the photosensitive material is processed the strength of the processing solutions is diminished and will eventually become exhausted. To prevent the continual weakening of the processing solution additional fresh processing solution is added to the tank solution at a rate equivalent to the rate of use and rate of carry out of the processing solution. The above maintains processing solution activity and volume. Typically the replenish is very small compared to the working processing tank volume. A typical ratio of replenishment per square foot of photosensitive. material for a large volume tank would be 0.00025 to 0.00075 of the tank volume. Since the above ratio is small the effect of pulsing delivery and cyclic variation of the replenishment delivery by 5 or 10% over time, does not have an immediate significant effect on the processing solution. Typical replenishment is accomplished by using a single standard bellow pump (like Gorman-Rupp single bellow metering pump mode number 13300-007). When replenishment is required the pump is turned on/off through known means and the replenishment solution is pumped in "doses" or "squirts" usually into the top of the main processing tank in close proximity to the recirculation system. As the bellows pump delivers solution to the top of the tank, the bellows pump is not experiencing any variable back pressure or head. As the replenishment in the large tank occurs, the pressure is only that of line restriction and gravity from the replenishment storage tanks to the solution delivery location. The pulsing delivery is acceptable as the ratio of replenishment to tank solution is very small. The above pump works well for large volume tanks, because the large volume of solution acts as a ballast. Replenishment calibration is typically a manual operation involving running the replenishment pump and measuring the solution output volume. This measuring device used is most often a graduated cylinder. The measured amount of solution is compared to the chemical manufacturers' specification for the type of photosensitive material and amount of replenishment solution required to be added. Successive timed measurements of replenishment solution delivery are made to determine the actual replenishment solution delivery rate. If adjustments are required, a manual adjustment of the bellows pump is made. Following the adjustment, the delivery of replenishment solution is again measured, and further adjustments are made until the delivery of replenishment solution is consistently at the required amount. During the above adjustment time the processor can not be used to process photosensitive materials. Thus, the processor would not be processing photosensitive materials when the pumps are being calibrated. U.S. Patent 5,179,404 discloses a processing apparatus wherein a narrow processing channel is formed between a rack and a tank. The photosensitive material is transported through the narrow channel by appropriate rollers contained in the rack and tank. Problems to be solved by the Invention The prior art utilized a manual time consuming procedure, which required an experienced operator to measure the replenishment delivery amounts prior to and following each calibration and adjustment of the replenishment pumps. Typically the calibration and adjustment of the pumps can take 30 minutes to 4 hours. Furthermore, the calibration and adjustments are subject to human error. If the accuracy of the processor is not maintained then the processor will not produce products having consistent quality. As the tank volumes are reduced, the ratio of replenisher delivery to tank volume significantly increased for example by a factor of 10 for a tank one tenth the volume of a standard 20 liter tank. Because the tank volume is small, the "pulse" or "squirt" delivery of the bellows pump has a greater impact on the tank solution consistency. This pulsing delivery creates pulsing or cyclic activity increases and decreases in the processor as its volume percentage is greater in the lower volume tank. The consistency of replenishment solution delivery is also more critical in smaller processing volumes. Another problem in the prior art is that when the pumps are turned on the rotational position of the pump varies. Similarly when the pumps are turned off the pump drive motor coasts stopping rotation at a unknown position. The above causes a variation of replenishment solution delivery over a constant time interval when the pumps are activated. Summary of the Invention This invention overcomes the disadvantages of the prior art by providing a replenishment pump calibration system which is integrated into the processor so that no manual measurement or special tools are required to set replenishment solution rates. As this is an integrated operation it can be done very quickly and accurately without requiring an experienced operator and excessive down time. In accordance with one aspect of the present invention, there is provided apparatus for processing photosensitive materials, the apparatus comprising:- at least one processing module each comprising a container, at least one processing assembly placed in the container, said processing assembly having a processing channel formed therein through which a processing solution flows, the processing channel having an entrance through which the material enters the processing solution and an exit through which the material exits the processing solution, recirculating means for recirculating the processing solution through the processing channel, and replenishing means for replenishing the processing solution, characterized in that the processing channel comprises at least 40% of the total volume of processing solution available for the processing module; the replenishment means is arranged to replenish the processing solution in a precisely controlled volume so as to provide a substantially uniform amount of processing solution in the apparatus. Advantageously, the replenishing means comprises at least one pump which outputs a uniform amount of processing solution, the pumps being are connected out of phase, calibration means for changing and verifying the rate of deliver of replenished processing solution, and a microprocessor coupled to a metering vessel to automatically measure the rate of delivery of replenished processing solution. By combining two or more bellows pumps together in parallel and equally offsetting the replenishment solution delivery cycle of each bellows pump, the "pulsing" may be smoothed to a more consistent solution delivery rate per rotation of the pump drive motor. A stepper motor may be used to drive the bellows pumps. Small delivery changes may be made by simply changing the stepper motor drive frequency. The pump drive frequency is directly proportional to the replenishment solution delivered. This allows the start and stop rotational position of the bellows pumps to be known. By combing the aforementioned bellows pumps and stepper motor with a constant metering vessel and control system automatic replenishment calibration may be achieved. Advantageous Effect of the Invention The above arrangement, provides a method for accurately replenishing processing solution through a low volume photographic material processing apparatus. This invention also permits start up and shut down of the replenishment pumps, while allowing the processor to produce products having consistent quality. Another advantage of this invention is that the calibration of the replenishment pumps requires minimal human intervention. Thus, reducing operation error. An additional advantage of the replenishment system is that the photographic processor may remain in operation while the replenishment system is being calibrated, checked or different solution replenishment rates are implemented. Brief Description of the Drawings For a better understanding of the present invention, reference will now be made, by way of example only, to the accompanying drawings in which:- Figure 1 is a perspective view of a processing module constructed in accordance with the present invention and which forms part of a tray processor; Figure 2 is a partially sectioned view of the module shown in Figure 1 illustrating one embodiment of a processing module according to the present invention for processing material having one emulsion surface; Figure 3 is a partially sectioned view similar to that shown in Figure 2, but of a second embodiment of a processing module according to the present invention; Figure 4 is a partially sectioned view similar to that shown in Figure 2, but of a third embodiment of a processing module according to the present invention for processing material having two emulsion surfaces; Figure 5 is a schematic view of a processing solution recirculation replenishment and calibration system of the apparatus in accordance with the present invention; and Figure 6 shows in detail a replenishment pump which can be used with the system shown in Figure 5. Detailed Description of the Invention Referring now to the drawings in detail, and more particularly to Figure 1, the reference character 10 represents a processing module, which may stand alone or be easily combined or adjoined with other processing modules 10 to form a continuous low volume unit for processing photosensitive materials. Processing module 10 includes: a container 11; an upturned entrance channel 100 (described in the description of Figure 2); an entry transport roller assembly 12; transport roller assemblies 13; an exit transport roller assembly 15; an upturned exit channel 101 (described in the description of Figure 2); high impingement slot nozzles 17a, 17b and 17c; a drive 16 and a rotating assembly 18, assembly 18 may be any known means for turning drive 16, i.e., a motor, a gear, a belt, a chain, etc. An access hole 61 is provided in container 11. Hole 61 is utilized for the interconnection of modules 10. Assemblies 12, 13 and 15 and slot nozzles 17a, 17b and 17c are positioned within the vicinity of the walls of container 11. Drive 16 is connected to roller assemblies 12, 13 and 15 and turning assembly 18 and assembly 16 is used to transmit the motion of assembly 18 to assemblies 12, 13 and 15. Roller assemblies 12, 13, and 15, and slot nozzles 17a, 17b and 17c may be easily inserted into or removed from container 11. Roller assembly 13 includes: a top roller 22; a bottom roller 23; tension springs 62, which holds top roller 22 in compression with respect to bottom roller 23; a bearing bracket 26; and a channel section 24 having a thin low volume processing channel 25. A narrow channel opening 27 (Figure 2) exists within section 24. Opening 27 on the entrance side of section 24 may be the same size and shape as opening 27 on the exit side of section 24. Opening 27 on the entrance side of section 24 may also be relieved, tapered or larger than the exit side of section 24 to accommodate rigidity variations of various types of photosensitive material 21. Channel opening 27 forms a portion of processing channel 25. Rollers 22 and 23 may be drive or driven rollers and are connected to bracket 26. Rollers 22 and 23 are rotated by intermeshing gears 28. Photosensitive material 21 is transported in either direction A or direction B automatically through processing channel 25 by roller assemblies 12, 13 and 15. Photosensitive material 21 may be in a cut sheet or roll format or photosensitive material 21 may be simultaneously in a roll and simultaneously in a cut sheet format. Photosensitive material 21 may contain an emulsion on either or both of its surfaces. When cover 20 is placed on container 11 a light tight enclosure is formed. Thus, module 10 with its associated recirculation system 60, which is described in the description of Figure 5, will be a stand alone light tight module which is capable of processing photosensitive material, i.e., a monobath. When two or more modules 10 are combined a multi-stage continuous processing unit may be formed. Figure 2 is a partially sectioned view of module 10 shown in Figure 1. Assemblies 12, 13 and 15, nozzles 17a, 17b and 17c and backing plate 9 are designed in a manner to minimize the amount of processing solution which is contained in processing channel 25, vessel 11, recirculation system 60 (Figure 5) and gaps 49a, 49b, 49c and 49d. At the entrance of module 10, an upturned channel 100 forms the entrance to processing channel 25. At the exit of module 10, an upturned channel 101 forms the exit to processing channel 25. Assembly 12 is similar to assembly 13. Assembly 12 includes: a top roller 30; a bottom roller 31; tension springs 62 (not shown) which holds top roller 30 to bottom roller 31; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 is formed by channel section 24. Rollers 30 and 31 may be drive or driven rollers and are connected to bracket 26. Assembly 15 is similar to assembly 13, except that assembly 15 has an additional two rollers 130 and 131, which operate in the same manner as rollers 32 and 33. Assembly 15 includes: a top roller 32; a bottom roller 33; tension springs 62 (not shown); a top roller 130; a bottom roller 131; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 32, 33, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Backing plate 9 and slot nozzles 17a, 17b and 17c are affixed to container 11. The embodiment shown in Figure 2 will be used when photosensitive material 21 has an emulsion on one of its surfaces. The emulsion side of material 21 will face slot nozzles 17a, 17b and 17c. Material 21 enters channel 25 between rollers 30 and 31 and moves past backing plate 9 and nozzle 17a. Then material 21 moves between rollers 22 and 23 and moves past backing plates 9 and nozzles 17b and 17c. At this point material 21 will move between rollers 32 and 33, and move between rollers 130 and 131 and exit processing channel 25. Conduit 48a connects gap 49a, via port 44a to recirculation system 60 via port 44 (Figure 5), which is more fully described in the description of Figure 5, and conduit 48b connects gap 49b, via port 45a to recirculation system 60 via port 45 (Figure 5). Conduit 48c connects gap 49c, via port 46a to recirculation system 60 via port 46 (Figure 5) and conduit 48d connects gap 49d, via port 47a to recirculation system 60 via port 47 (Figure 5). Slot nozzle 17a is connected to recirculation system 60 via conduit 50a and inlet port 41a via port 44 (Figure 5) and slot nozzle 17b is connected to recirculation system 60 via conduit 50b and inlet port 42a via inlet port 42 (Figure 5). Conduit 50c connects nozzle 17c, via inlet port 43a to recirculation system 60 via port 43 (Figure 5). Sensor 52 is connected to container 11 and sensor 52 is used to maintain a processing solution level 235 relative to conduit 51. Excess processing solution may be removed by overflow conduit 51. Textured surface 200 is affixed to the surface of backing plate 9 which faces processing channel 25 and to the surface of slot nozzles 17a, 17b and 17c that faces processing channel 25. Figure 3 is a partially sectioned view of an alternate embodiment of module 10 of Figure 2 in which material 21 has an emulsion on one surface and nozzles 17d, 17e and 17f are on the top portion of container 11. Assemblies 12, 13 and 15, nozzles 17d, 17e and 17f and backing plate 9 are designed in a manner to minimize the amount of processing solution which is contained in processing channel 25 and gaps 49e, 49f, 49g and 49h. At the entrance of module 10, an upturned channel 100 forms the entrance to processing channel 25. At the exit of module 10, an upturned channel 101 forms the exit to processing channel 25. Assembly 12 is similar to assembly 13. Assembly 12 includes: a top roller 30; a bottom roller 31; tension springs 62 (not shown) which holds top roller 30 in compression with respect to bottom roller 31, a bearing bracket 26; and a channel section 24. A portion of narrow channel opening 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 30 and 31 may be drive or driven rollers and are connected to bracket 26. Assembly 15 is similar to assembly 13, except that assembly 15 has an additional two rollers 130 and 131 which operate in the same manner as rollers 32 and 33. Assembly 15 includes: a top roller 32; a bottom roller 33; a tension spring 62 (not shown); a top roller 130; a bottom roller 131; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 32, 33, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Thus, it can be seen that a substantially continuous processing channel is provided. Backing plate 9 and slot nozzles 17d, 17e and 17f are affixed to container 11. The embodiment shown in Figure 3 will be used when photosensitive material 21 has an emulsion on one of its surfaces. The emulsion side of material 21 will face slot nozzles 17d, 17e and 17f. Material 21 enters channel 25 between rollers 30 and 31 and moves past backing plate 9 and nozzle 17d. Then material 21 moves between rollers 22 and 23 and moves past backing plates 9 and nozzles 17e and 17f. At this point material 21 will move between rollers 32 and 33 and move between rollers 130 and 131 and exit processing channel 25. Conduit 48e connects gap 49e, via port 44b to recirculation system 60 via port 44 (Figure 5) and conduit 48f connects gap 49f, via port 45b to recirculation system 60 via port 45 (Figure 5). Conduit 48g connects gap 49g, via port 46b to recirculation system 60 via port 46 (Figure 5) and conduit 48h connects gap 49h, via port 47b to recirculation system 60 via port 47 (Figure 5). Slot nozzle 17d is connected to recirculation system 60 via conduit 50d and inlet port 41b via inlet 41 (Figure 5) and slot nozzle 17e is connected to recirculation system 60 via conduit 50e and inlet port 42b via port 42 (Figure 5). Conduit 50f connects nozzle 17f, via inlet port 43b to recirculation system 60 via port 43 (Figure 5). Sensor 52 is connected to container 11 and sensor 52 is used to maintain a processing solution level 235 relative to conduit 51. Excess processing solution may be removed by overflow conduit 51. Textured surface 200 is affixed to the surface of backing plate 9 which faces processing channel 25 and to the surface of slot nozzles 17d, 17e and 17f which faces processing channel 25. Figure 4 is a partially sectioned view of an alternate embodiment of the processing module 10 shown in Figure 2 in which material 21 has an emulsion on both surfaces and nozzles 17g, 17h and 17i are on the top portion of container 11 facing one emulsion surface of material 21 and nozzles 17j, 17k, and 17L are on the bottom portion of container 11 facing the other emulsion surface of material 21. Assemblies 12, 13 and 15, nozzles 17g, 17h, 17i, 17j, 17k and 17L are designed in a manner to minimize the amount of processing solution which is contained in processing channel 25 and gaps 49i, 49j, 49k and 49L. At the entrance of module 10, an upturned channel 100 forms the entrance to processing channel 25. At the exit of module 10, an upturned channel 101 forms the exit to processing channel 25. Assembly 12 includes: a top roller 30; a bottom roller 31; tension springs 62 (not shown) which holds top roller 30 in compression with respect to bottom roller 31, a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 30, 31, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Assembly 15 is similar to assembly 13, except that assembly 15 has an additional two rollers 130 and 131 which operate in the same manner as rollers 32 and 33. Assembly 15 includes: a top roller 32; a bottom roller 33; tension springs 62 (not shown); a top roller 130; a bottom roller 131; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 32, 33, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Slot nozzles 17g, 17h and 17i are affixed to the upper portion of container 11. Slot nozzles 17j, 17k and 17L are affixed to the lower portion of container 11. The embodiment shown in Figure 4 will be used when photosensitive material 21 has an emulsion on both of its two surfaces. One emulsion side of material 21 will face slot nozzles 17g, 17h and 17i.and the other emulsion side of material 21 will face slot nozzles 17j, 17k and 17L. Material 21 enters channel 25 between rollers 30 and 31 and moves past and nozzles 17g and 17j. Then material 21 moves between rollers 22 and 23 and moves past nozzles 17h, 17k, 17i and 17L. At this point material 21 will move between rollers 32 and 33 and move between rollers 130 and 131 and exit processing channel 25. Conduit 48i connects gap 49i, via port 44c to recirculation system 60 via port 44 (Figure 5) and conduit 48j connects gap 49k, via port 45c to recirculation system 60 via port 45 (Figure 5). Conduit 48k connects gap 49L, via port 46c to recirculation system 60 and conduit 48L connects gap 49j, via port 47c to recirculation system 60 via port 47 (Figure 5). Slot nozzle 17g is connected to recirculation system 60 via conduit 50g via port 41 (Figure 5). Slot nozzle 17h is connected to recirculation system 60 via conduit 50h and inlet port 62 via port 42 (Figure 5). Conduit 50i connects nozzle 17i, via inlet port 63 to recirculation system 60 via port 43 (Figure 5). Slot nozzle 17j is connected to recirculation system 60 via conduit 50j and inlet port 41c via port 41 (Figure 5) and slot nozzle 17k is connected to recirculation system 60 via conduit 50k and inlet port 42c via port 42 (Figure 5). Slot nozzle 17L is connected to recirculation system 60 via conduit 50L and inlet port 43c via port 43 (Figure 5). Sensor 52 is connected to container 11 and sensor 52 is used to maintain a processing solution level 235 relative to conduit 51. Excess processing solution may be removed by overflow conduit 51. Material 21 enters upturned channel entrance 100, then passes through channel section 24 of channel 25 between rollers 30 and 31 and moves past nozzles 17g and 17j. Then material 21 moves between rollers 22 and 23 and moves past nozzles 17h and 17k, 17L and 17i. At this point material 21 will move between rollers 32 and 33 and exit processing channel 25. Textured surface 200 is affixed to the surface of slot nozzles 17g, 17h, 17i, 17j, 17k and 17L which face processing channel 25. Preferred embodiments of slot nozzles 17a, 17b, 17c, 17d, 17e, 17f, 17g, 17h, 17i, 17j, 17k, 17L are described in European publication no. 0 623 848, published 09 November 1994, entitled A Slot Impingement for an Automatic Tray Processor and European publication no. 0 623 847, published 09 November 1994, entitled Counter Cross Flow for an Automatic Tray Processor . Figure 5 is a schematic diagram of a processing solution recirculation replenishment and calibration system in accordance with the present invention. Module 10 is designed in a manner to minimize the volume of channel 25. The outlets 44, 45, 46 and 47 of module 10 are connected to sump 226. Sump 226 is connected to recirculating pump 80 via conduit 85. Recirculating pump 80 is connected to manifold 64 via conduit 63 and manifold 64 is coupled to filter 65 via conduit 66. Filter 65 is connected to heat exchanger 86 and heat exchanger 86 is connected to channel 25 via conduit 4. Heat exchanger 86 is also connected to control logic 67 via wire 68. Control logic 67 is connected to heat exchanger 86 via wire 70 and sensor 52 is connected to control logic 67 via wire 71. Solution replenishment vessel 245 is connected to metering pump 246 via conduit 247. Metering pump 246 is connected to metering vessel 248 via conduit 249. Metering vessel 248 is connected to manifold 64 via conduit 250. Metering vessel 248 is connected to replenishment vessel 245 via conduit 251, valve 252 and conduit 253. Metering pump 246, metering vessel 248, valve 252 and motor drive 255 are connected to microprocessor 254. The photographic processing chemicals which comprise the photographic solution are placed in replenishment vessel 245. The desired replenishment rate is entered into control logic 67 by any known means such as manually or scanning the desired information through the control panel of control logic 67. Metering pump 246 and metering vessel 248 are used to place the correct amount of chemicals in manifold 64, when photosensitive material sensor 210 senses that material 21 (Figure 1) is entering channel 25. Sensor 210 transmits a signal to control logic 67 via line 211. Control logic 67 sends a signal via wire 257 to microprocessor 254. Microprocessor 254 transmits a signal via wire 258 to motor driver 255. Motor driver 255 is the B & B Motor and Control Corp. gear motor driver No. CP-10PN-4 and motor 259 is the B & B Motor and Control Corp., motor model No. BV6G-60. B & B Motors and Control Corp. is located at Apple Hill Commons, Burlington, CT 06013. Microprocessor 254 is the Intel 8051 Microcontroller manufactured by Intel Corp. of 3065 Bowers Avenue, Santa Clara, CA 95051. Motor driver 255 transmits a signal to motor 259 via wire 260. Motor 259 may be a stepper motor or a motor which may be controlled to variable speeds. The above signal energizes motor 259 which causes replenishment solution to be pumped from replenishment vessel 245 through conduit 247 into pump 246. Pump 246 is a single bellows with 360° variable rotational speed whose speed can be varied during the 360° rotational to provide smooth nonpulsing solution output or pump 246 is a combination of two or more bellows which are connected together equally out of rotational phase with their input and output lines connected in parallel so that the solution delivery is smoothed to a more consistent solution delivery rate per rotation of the pump drive motor. Pump 246 pumps solution through conduit 249 into metering vessel 248. Thereupon the replenishment solution moves through conduit 250 into manifold 64. At start up of module 10 or when replenishment calibration is initiated valve 252 is opened which drains the contents of metering vessel 248 through conduit 253 into replenisher vessel 245. Valve 252 is then closed, microprocessor 254 signals motor driver 255 which starts motor 259 at a constant rate driving pump 246. Replenisher solution is pumped from replenisher vessel 245 via conduit 247 into metering vessel 248 via conduit 249 by pump 246. As the solution is pumped through metering vessel 248 it passes sensors 268, 269, 270, 271 and 272. Sensors 268, 269, 270, 271, 272 are used to sense the rate of solution flow through metering vessel 248. As metering vessel 248 is a constant volume vessel the replenishment rate may be determined by microprocessor 254. Thus, it can be seen the processing solution is pumped directly from the outlet passages to the inlet ports without use of a reservoir. The rate measured by sensors 268, 269, 270, 271, 272 is compared to the desired replenishment rate inputted into control logic 67 and transmitted to microprocessor 254. Microprocessor 254 signals motor driver 255 to speed up or slow down motor 259 as required to meet replenishment rate requirements. Manifold 64 introduces the photographic processing solution into conduit 66. The photographic processing solution flows into filter 65 via conduit 66. Filter 65 removes contaminants and debris which may be contained in the photographic processing solution. After the photographic processing solution has been filtered, the solution enters heat exchanger 86. Sensor 52 senses the solution level and sensor 8 senses the temperature of the solution and respectively transmits the solution level and temperature of the solution to control logic 67 via wires 71 and 7. For example, control logic 67 contains the series CN 310 solid state temperature controller manufactured by Omega Engineering, Inc. of 1 Omega Drive, Stamford, Connecticut 06907 and Intel 8051 Microcontrollers. Logic 67 compares the solution temperature sensed by sensor 8 and the temperature that exchanger 86 transmitted to logic 67 via wire 70. Logic 67 will inform exchanger 86 to add or remove heat from the solution. Thus, logic 67 and heat exchanger 86 modify the temperature of the solution and maintain the solution temperature at the desired level. Sensor 52 senses the solution level in channel 25 and transmits the sensed solution level to control logic 67 via wire 71. Logic 67 compares the solution level sensed by sensor 52 via wire 71 to the solution level set in logic 67. Logic 67 will inform microprocessor 254 via wire 261 to add additional solution if the solution level is low. Once the solution level is at the desired set point control logic 67 will inform microprocessor 254 to stop adding additional solution. Any excess solution may either be pumped out of module 10 or removed through level drain overflow 84 via conduit 81 into container 82. At this point the solution enters module 10 via inlets 41, 42 and 43. When module 10 contains too much solution the excess solution will be removed by overflow conduit 51, drain overflow 84 and conduit 81 and flow into reservoir 82. The solution level of reservoir 82 is monitored by sensor 212. Sensor 212 is connected to control logic 67 via line 213. When sensor 212 senses the presence of solution in reservoir 82, a signal is transmitted to logic 67 via line 213 and logic 67 enables pump 214. Thereupon, pump 214 pumps solution into manifold 64. When sensor 212 does not sense the presence of solution, pump 214 is disabled by the signal transmitted via line 213 and logic 67. When solution in reservoir 82 reaches overflow 215 the solution will be transmitted through conduit 216 into reservoir 217. The remaining solution will circulate through channel 25 and reach outlet lines 44, 45, 46 and 47. Thereupon, the solution will pass from outlet lines 44, 45, 46 and 47 to sump 226. The solution will exit sump 226 via conduit line 85 and enter recirculation pump 80. The photographic solution contained in the apparatus of this invention, when exposed to the photosensitive material, will reach a seasoned state more rapidly than prior art systems, because the volume of the photographic processing solution is less. Figure 6 illustrates pump 246 in more detail. Pump 246 comprises bellows 275, 276 and 277, crank shaft 278 and connecting rods 279, 280 and 281. Shaft 278 is respectively connected to bellows 275, 276 and 277 by connecting rods 281, 280 and 279. Connecting rods 279, 280 and 281 are interconnected to shaft 278, 120° out of rotational phase with each other. One skilled in the art would realize that other pumps or devices may be used in place of or in combination with bellows pumps, i.e., piston pumps, and peristaltic pumps, etc. Also the rotational speed of a single bellows pump may be varied during each rotational cycle to smooth out or reduce the pulsing deliver of the replenished solution. When pump drive motor 259 is energized shaft 278 will rotate and connecting rods 279, 280 and 281 will alternately compress and expand bellows pumps 275, 276 and 277. Thereupon drawing replenishment solution through conduit 247 and forcing replenishment solution out through conduit 249. Bellows inlets 282, 283 and 284 are connected to replenishment vessel 245 (Figure 5) via conduit 247. Outlets 285, 286 and 287 are connected to metering vessel 248 via conduit 249. A processor made in accordance with the present invention provides a small volume for holding processing solution. As a part of limiting the volume of the processing solution, a narrow processing channel is provided. The processing channel 25, for a processor used for photographic paper, should have a thickness t equal to or less than about 50 times the thickness of paper being processed, preferably the thickness t is equal to or less than about 10 times the paper thickness. In a processor for processing photographic film, the thickness t of the processing channel 25 should be equal to or less than about 100 times the thickness of photosensitive film, preferably, equal to or less than about 18 times the thickness of the photographic film. An example of a processor made in accordance with the present invention which processes paper having a thickness of about 0.2mm (0.008") would have a channel thickness t of about 2mm (0.080") and a processor which process film having a thickness of about 0.14mm (0.0055") would have a channel thickness t of about 2.54mm (0.10"). The total volume of the processing solution within the processing channel 25 and recirculation system 60 is relatively smaller as compared to prior art processors. In particular, the total amount of processing solution in the entire processing system for a particular module is such that the total volume in the processing channel 25 is at least 40% of the total volume of processing solution in the system. Preferably, the volume of the processing channel 25 is at least about 50% of the total volume of the processing solution in the system. In the particular embodiment illustrated, the volume of the processing channel is about 60% of total volume of the processing solution. Typically the amount of processing solution available in the system will vary on the size of the processor, that is, the amount of photosensitive material the processor is capable of processing. For example, a typical prior art microlab processor, a processor which processes up to about 0.46m 2 /min (5ft 2 /min) of photosensitive material (which generally has a transport speed less than about 1.27m/min (50" per minute) has about 17 liters of processing solution as compared to about 5 liters for a processor made in accordance with the present invention. With respect to typical prior art minilabs, a processor that processes from about 0.46m 2 /min (5ft 2 /min) to about 1.39m 2 /min (15ft 2 /min) of photosensitive material (which generally has a transport speed from about 1.27m/min (50in/min) to about 3.05m/min (120in/min)) has about 100 liters of processing solution as compared to about 10 liters for a processor made in accordance with the present invention. With respect to large prior art lab processors that process up to 4.6m 2 /min (50ft 2 /min) of photosensitive material (which generally have transport speeds of about 2.13 to 18m/min (7 to 60ft/min)) typically have from about 150 to 300 liters of processing solution as compared to a range of about 15 to 100 liters for a large processor made in accordance with the present invention. In a minilab size processor made in accordance with the present invention designed to process 1.39m 2 (15ft 2 ) of photosensitive material per minute would have about 7 liters of processing solution as compared to about 17 liters for a typical prior art processor. In certain situations it may be appropriate to provide a sump in the conduits 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h, 48i, 48j, 48k, 48L and/or gaps 49a, 49b, 49c, 49d, 49e, 49f, 49g, 49h, 49i, 49j, 49k, 49L so that vortexing of the processing solution will not occur. The size and configuration of the sump will, of course, be dependent upon the rate at which the processing solution is recirculated and the size of the connecting passages which form part of the recirculatory system. It is desirable to make the connecting passages as small as possible, yet, the smaller the size of the passages, for example, in the conduits 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h, 48i, 48j, 48k, 48L from the gaps 49a, 49b, 49c, 49d, 49e, 49f, 49g, 49h, 49i, 49j, 49k, 49L to the pump, the greater likelihood that vortexing may occur. For example, in a processor having a recirculatory rate of approximately 11.36 to 15.141/min (3 to 4 US gallons/min), there is preferably provided a sump such that a head pressure of approximately 100mm (4") at the exit of the tray to the recirculating pump can be maintained without causing vortexing. The sump need only be provided in a localized area adjacent the conduits 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h, 48i, 48j, 48k, 48L of the tray. Thus, it is important to try to balance the low amount of volume of the processing solution available to the flow rate required of the processor. In order to provide efficient flow of the processing solution through the nozzles into the processing channel, it is desirable that the nozzles/openings that deliver the processing solution to the processing channel have a configuration in accordance with the following relationship: .586 ≤ F A ≤ 23.4 wherein: F is the flow rate of the solution through the nozzle in litres per minute; and A is the cross-sectional area of the nozzle provided in centimetres squared. Providing a nozzle in accordance with the foregoing relationship assures appropriate discharge of the processing solution against the photosensitive material. The above specification describes a new and improved apparatus for processing photosensitive materials. It is realized that the above description may indicate to those skilled in the art additional ways in which the principles of this invention may be used without departing from the claimed invention. It is, therefore, intended that this invention be limited only by the scope of the appended claims.

Claims: Apparatus for processing photosensitive materials (21), the apparatus comprising:- at least one processing module (10) each comprising a container (11), at least one processing assembly (9, 17a, 17b, 17c; 17d, 17e, 17f; 17g, 17h, 17i; 17j, 17k, 17L) placed in the container (11), said processing assembly having a processing channel (25) formed therein through which a processing solution flows, the processing channel (25) having an entrance (100) through which the material enters the processing solution and an exit (101) through which the material exits the processing solution, recirculating means (64, 65, 80, 86, 226) for recirculating the processing solution through the processing channel (25), and replenishing means (245, 246, 248, 254, 259, 268, 269, 270, 271, 272, 275, 276, 277) for replenishing the processing solution characterized in that the processing channel comprises at least 40% of the total volume of processing solution available for the processing module (10); the replenishment means is arranged to replenish the processing solution in a precisely controlled volume so as to provide a substantially uniform amount of processing solution in the apparatus. Apparatus according to claim 1, wherein the replenishing means (245, 246, 248, 254, 255, 259, 268, 269, 270, 271, 272) comprises at least one pump (246; 275, 276, 277) which outputs a uniform amount of processing solution. Apparatus according to claim 2, wherein the replenishing means (245, 246, 248, 254, 255, 259, 268, 269, 270, 271, 272, 275, 276, 277) comprises two or more pumps (275, 276, 277) whose pulsed outputs are connected out of phase, thereby to smooth delivery of the processing solution to the processing channel. Apparatus according to any one of claims 1 to 3, wherein the replenishing means (245, 246, 248, 254, 255, 259, 268, 269, 270, 271, 272, 275, 276, 277) includes calibration means (254, 268, 269, 270, 271, 272) for changing and verifying the rate of deliver of replenished processing solution. Apparatus according to claim 4, wherein the replenishing means (245, 246, 248, 254, 255, 259, 268, 269, 270, 271, 272, 275, 276, 277) further comprises a microprocessor (254) coupled to a metering vessel (248) to automatically measure the rate of delivery of replenished processing solution. Apparatus according to any one of the preceding claims, wherein each processing assembly includes at least one discharge opening (17a, 17b, 17c; 17d, 17e, 17f; 17g, 17h, 17i; 17j, 17k, 17L) for introducing processing solution to the processing channel (25) and at least one outlet (48a, 48b, 48c; 48d, 48e, 48f; 48g, 48h, 48i; 48j, 48k, 48L) for allowing processing solution to exit the processing channel (25), the recirculating means (64, 65, 80, 86, 226) recirculating the processing solution from each outlet (48a, 48b, 48c; 48d, 48e, 48f; 48g, 48h, 48i; 48j, 48k, 48L) directly to each discharge opening (17a, 17b, 17c; 17d, 17e, 17f; 17g, 17h, 17i; 17j, 17k, 17L) via the replenishing means (245, 246, 248, 254, 255, 259, 268, 269, 270, 271, 272). Apparatus according to any one of the preceding claims, wherein each processing module (10) further includes at least one transport assembly (12, 13, 15) disposed adjacent each processing assembly (9, 17a, 17b, 17c; 17d, 17e, 17f; 17g, 17h, 17i; 17j, 17k, 17L) for transporting the photosensitive material (21) from the channel entrance (100) to the channel exit (101), each transport assembly (12, 13, 15) forming a portion of the processing channel (25). Apparatus according to any one of the preceding claims, wherein the processing channel (25) comprises at least 60% of the total volume of the processing solution for the processing module (10). Apparatus according to any one of the preceding claims, wherein the processing assembly (9, 17a, 17b, 17c; 17d, 17e, 17f; 17g, 17h, 17i; 17j, 17k, 171) is removably mounted in the processing module (10), and the processing channel (25) is formed in the processing assembly. Apparatus according to any one of the preceding claims, wherein the thickness of the processing channel is about 2.0mm, preferably for use with photosensitive paper material (21), or is about 2.54mm, preferably for use with photosensitive film material (21). Apparatus according to claim 2 or 3, wherein the or each pump is selected from the group consisting of bellows pumps, piston pumps and peristaltic pumps. Apparatus according to claim 1, wherein the replenishing means comprises a pump that has a delivery output that is controlled by adjusting the rotational speed of the pump, thereby to smooth delivery of the processing solution to the processing channel. Apparatus according to claim 1, comprising calibration mean coupled to said replenishing means for changing and verifying the rate of delivery of replenished processing solution.

Inventors: HORTON ROBERT LOUIS, PATTON DAVID LYNN, ROSENBURGH JOHN HOWARD, HORTON, ROBERT LOUIS, PATTON, DAVID LYNN, ROSENBURGH, JOHN HOWARD, HORTON, ROBERT LOUIS, C/O EASTMAN KODAK COMP., PATTON, DAVID LYNN, C/O EASTMAN KODAK COMP., ROSENBURGH, JOHN HOWARD , C/O EASTMAN KODAK COMP.
Applicants: EASTMAN KODAK CO, EASTMAN KODAK COMPANY
Application year: 1994
Main classification: G03D3
IPC codes: G03D5, G03D3